PreparationFor dressing: Whisk shallot, vinegar, and mustard in small bowl. Gradually whisk in both oils. Season dressing with salt and pepper. DO AHEAD:Can be made 1 day ahead. Cover; chill. Bring to room temperature and rewhisk before using salad. For salad: Cook green beans in large pot of boiling salted water just until crisp-tender, 3 to 4 minutes. Using slotted spoon, transfer beans to colander; rinse with cold water. Cook wax beans and haricots verts separately in same pot of boiling salted water, 3 to 4 minutes for wax beans and 2 to 3 minutes for haricots verts. Transfer to colander; rinse with cold water. DO AHEAD:Can be made 1 day ahead. Wrap green beans, wax beans, and haricots verts separately in paper towels. Enclose in resealable plastic bag and chill. Combine all beans and frisée in large bowl. Toss with dressing. Transfer salad to serving platter; sprinkle with walnuts, herbs, and pepper. Top with cheese.
PreparationFor dressing: Whisk shallot, vinegar, and mustard in small bowl. Gradually whisk in both oils. Season dressing with salt and pepper. DO AHEAD:Can be made 1 day ahead. Cover; chill. Bring to room temperature and rewhisk before using salad. For salad: Cook green beans in large pot of boiling salted water just until crisp-tender, 3 to 4 minutes. Using slotted spoon, transfer beans to colander; rinse with cold water. Cook wax beans and haricots verts separately in same pot of boiling salted water, 3 to 4 minutes for wax beans and 2 to 3 minutes for haricots verts. Transfer to colander; rinse with cold water. DO AHEAD:Can be made 1 day ahead. Wrap green beans, wax beans, and haricots verts separately in paper towels. Enclose in resealable plastic bag and chill. Combine all beans and frisée in large bowl. Toss with dressing. Transfer salad to serving platter; sprinkle with walnuts, herbs, and pepper. Top with cheese.